Irrespective of the database version, there are a number of considerations we need to be aware of before we start the tuning process. Firstly, we must consider the underlying system and its ability to perform. Secondly, we must benchmark our current configuration so that we have a clear understanding of the performance gains achieved through tuning. For GoldenGate, this typically comprises of a basic setup with a single Extract, data pump, and Replicat process. Later, we will tune parameters and/or switch on features, taking a new benchmark at each stage. The secret is not to make too many changes to your environment before each performance evaluation. Furthermore, as discussed in the previous chapter, respective monitoring and measurement needs to be employed proactively to compare the results of each test.

Let's start by taking a look at the source of data that GoldenGate needs for replication to work the online redo logs.